Radiotelephony



Patented July 14, 1925.

UNITED $TATES PA TENT OFFICE.

MARIUS LATOUR, OF PARIS, FRANCE, ASSIGNOR TO LATOUR CORPORATION, OF JERSEY CITY, NEW JERSEY, A GORPORA'IION OF DELAWARE.

n-AnIo'rELnPHoNY.

No Drawing.

i Application filed August 29, 1921. Serial No. 496,650.

cmurnnunnnn'rm rnovrsrons or run ACT or Manon a, 1921, 41 srar. n, 1313.)

To all whom it may concern:

Be it known that I, MARIUS LA'roun, a citizen of- France, and resident of Paris, France, have invented certain new and useful Improvements in Radiotelephony (for which I have'filed an application in France; Febru ary 14:, 1917, resulting in French Patent No. 493,924, granted May 16', 1919) of which the following is a specification.

It has already been demonstrated that the use of a local continuous current wave source in awireless telegraph receiving station in ac cordance with the so-called heterodyne principle, results in a marked amplification of received signals.-

Heretofore, such local source was used only for the receiving of telegraphic signals. In accordance with the present invention, the use of a local continuous current wave 2 generator isextended to the reception in wireless telephony. v By establishing a sufficiently low or sufficiently high difference between the frequencies of the received and locally generated oscillations, the arrangement will be adjusted so that the permanent sound thus obtained will not interfere with the intelligibility of the sounds corresponding with the speech.

This method of receiving enables one to make sure of the functioning of the. corresponding station.

Having described my invention, what I claim is:

1. The method of receiving telephonic signals transmitted by highfrequency oscillations which consists'in superimposing locally generated high frequency oscillations on the received oscillations and adjusting the difference of the locally generated fre quency and the signal frequency within the limits of audibility so that the beat note does not interfere with the speech.

2. The method of receiving telephonic signals transmitted by high frequency oscillatlons through space whlch consists in super imposing locally generated continuous high frequency oscillations on the received oscillat ons and adjusting the beat frequency to glvean audible tone considerably higher or considerably lower than the normal speech frequencies.

3. The combination with means responsive to modulated carrier waves of means associated with said responsive means for producing audible beat notes from said carrier waves that do not interfere with'the'rnodulated frequencies. I

4. The combination of means responsive to carrier waves modulated by audible frequencies, of means associated with the said responsive means for producing audible beat notes from said carrier waves that do not interfere with the modulated audible fre quencies.

' 5. The combination with means responsive to'carrier waves modulated by speech frequencies of means associated with said responsive means for producing audible beat notes from said carrier waves that do not interfere with the speech frequencies.

MARIUS LATOUR. 

